Buffer Return on File Downlink Component

[ebenezerarunkumar]

Is there a reason why Buffer Returns on the File Downlink Component are only allowed during the WAIT and CANCEL states and not also during COOLDOWN mode?

// Non-ignored buffers cannot be returned in "DOWNLINK" and "IDLE" state. Only in "WAIT", "CANCEL" state. FW_ASSERT(this->m_mode.get() == Mode::WAIT || this->m_mode.get() == Mode::CANCEL, static_cast<FwAssertArgType>(this->m_mode.get()));

fprime/Svc/FileDownlink/FileDownlink.cpp

Line 150 in 2d3e09b

// Non-ignored buffers cannot be returned in "DOWNLINK" and "IDLE" state. Only in "WAIT", "CANCEL" state.

[LeStarch]

My understanding is that the component would always be WAITing for a buffer to return. The only other state it could be in is CANCEL because this state could arise from a CANCEL command.

Did you see the component be in another state while waiting for buffers to return?

[ebenezerarunkumar]

Yes, I was testing some code and hit that assert because I was in COOLDOWN mode. I eventually realized I had accidentally put the FileDownlink component on a 10 Hz RG instead of a 1 Hz RG, which made my cycleTime setting wrong in the configuration. Fixing that seemed to solve the issue.

That said, when I tried to reproduce the error in the Ref deployment by setting the cycle time config value to 10× longer than the RG that the FileDownlink component was connected to, I didn’t see the same error. This makes me wonder if my issue was actually caused by some thread priority/race condition in my FreeRTOS deployment.